[SOLVED] Interupt 16f887, 20MHz

[tvojmuc]

OK..I'm beginner so please be gently

How to use interrupt:
I have 16f887 PIC
BCD decoder on D0,1,2,3 and 4 led on B0,1,2,3
With interrupt routine I would like to read BCD code and then turn on LED
my code: -> and is not working

program LIGHT

 dim pre as byte


sub procedure interrupt ' Interrupt routine
'PORTE.0 = 1     'just to see int
'delay_ms(500)
pre =  PORTD
'PORTE.0 = 0       'just to see int
'delay_ms(500)
TMR0 = 155              ' Timer0 (or counter) returns its initial value
INTCON = 0x20           ' Bit T0IE is set, bit T0IF is cleared
end sub


main:
OPTION_REG = 0x04       ' Prescaler (1:32) is assigned to Timer0
TMR0 = 155              ' Timer0 counts from 155 to 255
INTCON = 0xA0           ' Enable interrupt on TMR0 overflow
TRISB = %00000000    'output = 0
TRISD = %11111111    'input = 1
TRISE.0 = 0          'output = 0
TRISE.1 = 0          'output = 0
zacetek:
PORTE.1 = 1      'just to see progress
delay_ms(500)
select case pre
case 0
PORTB = 1
case 1
PORTB = 2
case 2
PORTB = 4
case 3
PORTB =8
end select
 PORTE.1 = 0         'just to see progress
delay_ms(500)
goto zacetek
  
  
end.

 

[Tahmid]

Hi,
Try this:

program BCD887

dim pre as byte


sub procedure interrupt ' Interrupt routine
pre =  PORTD
TMR0 = 155              ' Timer0 (or counter) returns its initial value
T0IF_bit = 0 'Timer flag is cleared, interrupt is enabled on its own
end sub


main:
     ANSEL = 0
     ANSELH = 0
     OPTION_REG = 0x04       ' Prescaler (1:32) is assigned to Timer0
     TMR0 = 155              ' Timer0 counts from 155 to 255
     INTCON = 0xA0           ' Enable interrupt on TMR0 overflow
     TRISB = %00000000    'output = 0
     TRISD = %11111111    'input = 1
     TRISE.B0 = 0          'output = 0
     TRISE.B1 = 0          'output = 0
     PORTB = 0 'PORTB initially has some value that is cleared
     while true
           PORTE.B1 = 1      'just to see progress
           delay_ms(500)
           select case pre
                  case 0
                       PORTB = 1
                  case 1
                       PORTB = 2
                  case 2
                       PORTB = 4
                  case 3
                       PORTB =8
           end select
           PORTE.B1 = 0         'just to see progress
           delay_ms(500)
     wend


end.

16F887 has ADC inputs at PORTB. To use PORTB as digital I/O, you must disable ADC by:

ANSEL = 0
ANSELH = 0

Read more about it in ADC section.

Hope this helps.
Tahmid.

---------- Post added at 15:40 ---------- Previous post was at 15:35 ----------

In the ISR, only clear the flag, you don't need to set the interrupt again.
When you declare a port as output by setting the tris bits, it has an initial value, that should be cleared.

I showed these in the code.

Hope you understood.
Tahmid.

 

[tvojmuc]

THX
When I will be back home I will test this.
Thank you really!

 

[tvojmuc]

Thx
Sorry for late response, but I was just come home from business trip
It's working..I change a little structure bit but now is working.
I’m trying to build something light sound dependent fleshing light or bather like spectrum-analyzer but only 4 or 8 canal. Do you have any idea or code for that? I’m trying with FF algorithm but there is nothing to found in VB code that I will be able to understand easily. Maybe some other method or principle....suggest whatever!

 

[tvojmuc]

Please...have someone some idea to create sound base light show?

 

[Tahmid]

I'm not sure what you mean, could be a little more specific. Is it something like a disco lighting system that changes colour according to sound input?

 

[tvojmuc]

Yes correct 4 to 8 channel light show....this I would like to prefer, but each channel should be separate frequency channel.
thx